The periodic table is arranged according to increasing

• # of protons & neutrons (atomic mass)

• # of protons (atomic number)

• # of neutrons

• # of neutrons and electrons

The period (row) number tells you 

• how many energy levels each element in that period have.
• how reactive the element is.
• how nonreactive the element is.
• whether the element is a metal or nonmetal.

Elements in period (row) 3 have

• 3 electrons in their outer energy level
• 3 energy levels
• 3 as an atomic number
• full outer energy levels

Elements in group (column) one have

• one electron in their outer energy level
• one energy level
• a full outer energy level
• same atomic numbers

Elements in the same group (column) 

• have the same number of energy levels.
• are either all metals or nonmetals.
• have the same atomic mass.
• have the same number of outer electrons in the outer energy level.

So therefore elements in group (column) one are

• stable
• nonreactive
• reactive
• gases

Elements to the left of the zigzag line are

• liquids
• nonmetals
• nonreactive
• metals

Elements to the right of the zigzag line are

• nonmetals
• metals
• solids
• reactive

Based on its location on the periodic table, oxygen (O) is a 

• metalloid
• nonmetal
• metal
• solid

Tags

NGSS.MS-PS1-1

Based on its location on the periodic table, Lithium (Li) has _______ energy levels.

• 1
• 2
• 3
• 4